Rotary drying apparatus



Dec. 1, 1925- 1.564.058

s. s. GETTINGS ET AL ROTARY DRYING APPARATUS Filed Sept. 2'7, 1924 4' Sheets-Sheet 1 =5 N V In 2): Zofs:

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s. s. GETTINGS ET AL ROTARY DRYING APPARATUS Filed Sept. 27, 1924 4 Sheets-Sheet 5 Dec; 1,1 r 1.564.058

5. S. GETTINGS ET AL ROTARY DRYING APPARATUS Filed Sept. 27, 1924 4 Sheets-Sheet 4 Invembrs:

Patented Dec. 1,- 1925.

UNITED STATES PATENT orrics.

SYDNEY SALTER GETTING-S AND WALTER LIGHT BQDMAN, 0F DOBKING, ENGLAND, ASSIGNORS TO JAMES MITCHELL THOMAS JOHNSTON, OF LONDON, ENGLAND.

ROTARY DRYING- APPARATUS.

Application filed September 27, 1924.

To all whom it may concern:

Be it known that we, SYDNEY SALTER GETTINGS and WVALTER LIGHT BODMAN, sub jects of the King of England, and both residing at Dorking, in England, have 111- vcnted certain new and useful Improvements in Rotary Drying Apparatus, of which the following is a specification.

This invention relates to drying apparatus for discrete materials such as sand, stone chippings and the like, and is intended more particularly for the drying of such materials in the preparation of road surfaces.

The improved apparatus is of the type employing a rotary drum and arranged within a heating chamber or casing, the material being passed through the drum from end to end as it revolves and being exposed to the heat of fiue gases circulating therein from a fire box or furnace.

According to the present invention the rotary drum is suspended by chains, cables or bands which extend around the drum and around wheels secured to a driving shaft situated above the drum, such chains or the like serving to drive the drum as well as to support it. The ends of the drum can thus be left completely open, one end practically making a joint with the end plate of the casing connected to the chimney and the other end projecting into an enlarged end of the casing into which the drum discharges its contents upon a delivery chute.

The invention is hereafter described with reference to the accompanying sheets of drawings, in which Figure 1 is a part-sectional elevation of the improved drying apparatus.

Figure 2 is a plan of the same.

Figure 3 is an end view.

Figure 4 is a longitudinal sectional elevation of a simplified construction.

Referring to Figures 1, 2 and 3, the rotary drum 1 is fitted internally with spirally arranged ribs 2 which may be set at an angle of thirty degrees for example, the pitch being preferably increased towards the outlet end. This drum is rotated by pitch chains 3 engaging sprocket teeth 011 circular hoops or rings 4 secured upon the outside of the drum. The chains 3 are driven by sprockets 5 mounted on a shaft 6 which is supported in suitable brackets 7 upon the top of a casing 8 which encloses Serial No. 740,256.

the heating chamber. The shaft 6 is shown rotated by worm gearing 9 driven in any suitable manner, for example by chain gearing from an engine mounted on the frame.

The heating chamber 8 is shown provided at one end with a flue 10 and at the opposite end with an enlarged chamber 11. The open end of the drum 1 adjacent to the flue is in effect closed by the contiguous end plate of the casing 8, the hot gases from the interior of the drum being caused to pass through the end-plate to thefiue 10. The opposite end of the drum 1 extends into the chamber 11, so as to allow the hot gases to enter this open end of the drum.

The fire-box 12 is shown fitted with an oil-burner 13; obviously other heating means such as a solid-fuel furnace may be employed and likewise the position of the fire-box may be altered.

The gases from the fire-box pass as indicated by the arrows, around the exterior of the drum into the chamber 11 returning through the drum 1 and passing out by the flue 10. The stones and like material are fed into the upper end of the drum through a hopper 14 during the passage of this material around and along the drum it is compelled by the action of the ribs 2 to fall through the stream of heated gases.

The drum 1 is also provided at its lower end with scoops 15 serving to discharge its contents on to a chute 16, which is preferably fitted with a hinged flap 16 to retain a portion of the dried material so as to form a trap to prevent entrance of air at this point. i

The casing 8 may be mounted on a chassis having wheels 17 and provided with a coupling or towing hitch 18. The chamber or casing 8 may be made of constructional steel framed in a suitable manner and effectively covered with lagged plates.

The chains 3 pass into the casing 8 by way of slots or apertures 8 in the top plate of the casing 8 which also supports the driving shaft 6. This method of suspending the drum does away with trunnions or bearings, though guide rollers 19 may, if desired, be fitted within the casing to bear on the exterior of the drum and steady the latter.

The walls of the drum 1 may be reinforced by rings or bars as required, and they are provided with non-perforated zones closed chamber.

indicated at 1 adjacent to the driving chains 3 and guide rollers 19 to prevent material falling, out from the drum and upon the moving parts.

The discrete material may for instance be admitted to the interiorv of the drum 1 through an inclined chute leading to the hopper 14 at one end of the heating chamber, a flap or door being provided to close automatically after the charge has been introduced.

Figure 4 represents a modified construction in which the fire-box 12 is arranged at the opposite end to the fine 10; the chamber 11 in direct communication with the fire-box, so that the gases from the fire-box 12 pass at once into the open and lower end of the drum. The chains 3 carrying the rotary drum 1 are preferably arranged towards the other end and centre so as to be away from the heat of the furnace.

This apparatus possesses the following advantages: It is a simple machine and easy to construct and operate. The drum is suspended by the chains3 ina practically Part of the drum is directly over the fire-box so that the drying efl'ect produced by the flue gases inside the drum is assisted or completed by the heating due to the walls of the drum. Very little power is required; for instancea drum 12 ft. in length and 8 ft. in diameter, weighing approximately one ton when charged, can be revolved at sufficient speed by about 1 H. P. The drum is absolutely unaif'eeted byexpansion and contraction because it is not tied at any point. The drum is both externally fired and internally heated, the result'being to provide arevolving hot=plate, on which wet sand or fine material falling thereon is cracked and broken up, permitting the escape 'of steam-and making it very easy' to present surfaces to the *fiowing gases for the internaldrying.

lVe claim.

1. In a drying apparatus of the kind'described, in combination, a heating-chamber,

a rotatable drum havin its axis substantially horizontal and situated within the heating-chamber, a driving shaft having its axis parallel to that of the drum and ,situated outside the heating-chamber, a plurality of driving Wheels on said shaft, and a plurality of endless flexible driving and supporting members each extending around one of said wheels and the drum and through apertures in the wall of the heating-chamber.

2. In a drying apparatus of the kind described, in combination, van open-ended rotatable drum having its axis substantially horizontal, flexible suspending means extending beneath said drum, supports for said means, means for moving said suspending means to rotate said drum, a heatingchamber within which the drum is suspended having one wall transverse to the drum-axis in close proximity to one end of the drum and the opposite wall spaced from the other end of the drum.

3. In a drying apparatus of the :kind de scribed, in combination, a rotatable drum having its axis substantially horizontal, flexible suspending means extending beneath said drum, a casing enclosing the drum and having apertures therein for the passage of the said suspending means, supports for said means external to the heating-chan'iber and means for moving said means to rotate said drum.

4. In a drying apparatus of the kind described, in combination, a rotatable drum having its axis substantially horizontal and having perforated zones and non-perforated zones, the latter extending completely around the drum, flexible suspending means extending beneath the drum in the non-perforated zones thereof, supports for said means and means for moving said means to rotatethe drum.

In testimony whereof we have signed our names 'to this specification SYDNEY, SALTERGETTINGS- WALTER LIGHT BODMAN. 

